When it comes to siblings, they usually fall into two categories. One sibling may be considered The Reliable One and is often the subject of Parental Favoritism, while one is usually seen as a Black Sheep, and may be treated as The Un-Favourite. Often they may make a Foolish Sibling, Responsible Sibling pair, or their relationship results in Successful Sibling Syndrome.
However, over time, maybe the lesser sibling changes their ways, applies themselves, and becomes more successful and more popular. Perhaps this sibling suffered from Middle Child Syndrome and gained the ambition to succeed so they can have a little attention and credit. Or perhaps a stroke of luck changes the fortunes of the lesser sibling. Meanwhile, the sibling everyone looked up to had a fall from grace. Now the sibling that everybody thought would fail has taken the other sibling's place as the one everyone looks up to.
- There are honestly about a million that begin this way: a couple has three children, the youngest of whom seems to be lazy and/or stupid, yet winds up succeeding at whatever quest their siblings failed at.
- Cinderella, in its many variations and adaptations, has the title character treated poorly by her stepmother and stepsisters, but in the end Cinderella is the one that wins the heart of the prince and marries him.
- In The Sword in the Stone, Arthur, aka Wart, is seen as the inferior (adoptive) brother. However, he grows up to be King Arthur.
- In Aquaman (2018), Orm becomes the king of Atlantis, despite not being the first-born son of queen Atlanna, while first-born half-sibling Arthur is shunned by him and lives on the surface. However, Orm is ruthless and tries to wage war against the surface world, while Arthur succeeds in gaining the trident of Atlantis' first king, making him the true ruler of Atlantis. In the end, Arthur defeats Orm and takes his rightful place on the throne.
- In Gattaca, because of Fantastic Racism over who is genetically optimised, the older Vincent is shunned and looked down on compared to his younger brother Anton. However, in a swimming race, Vincent managed to beat his genetically-superior brother and Anton had a complex about that loss since. Ultimately, Vincent gets to be an astronaut while Anton is the literally more down-to-Earth police detective.
- In The King's Speech, nobody expects much of Prince Albert because of his shy personality and severe stutter, but when his older brother Edward abdicates the throne, he becomes King George VI of England.
- In A League of Their Own, older sister Dottie is the All-Star in her hometown, in the baseball league, and even with her parents. But younger sister Kit ends up being the one who hits the grand-slam home run that wins the Big Game. This is made all the more dramatic by the catcher Dottie literally dropping the ball, allowing Kit to get home safe.
- Stand by Me: Gordie was The Un-Favourite and largely ignored by his parents who only cared about their athletic son Denny. Denny was already killed in a car accident by the time the movie started, while Gordie will eventually become a Family Man and a writer.
- Wilbur from Charlotte's Web was born the runt of his litter, but thanks to Charlotte and her webs, he becomes a famous tourist attraction and wins a special prize at the county fair.
- Matilda: Despite her intelligence, the title character is horribly dismissed and mistreated by her parents, who clearly prefer her brother Michael over her. Matilda eventually discovers she has psychokinetic powers which she uses to her advantage, and towards the end she's also Happily Adopted by her nice teacher who recognised her genius.
- Whateley Universe:
- Bryan St. Claire, The Unfavorite, compared to his sister, Paige, is the one who gets superpowers.
- Jesse James Harrow, the one who had to babysit his younger siblings, and didn't have a gimmick like his older siblings, ended up netting a windfall of supernatural power on his birthday. Including the Gender Bender transformation she was primarily after.
- One episode of The Andy Griffith Show has Otis pretend to be a deputy in order to impress his brother, who the family always looked up to. It turns out that Otis' brother is now a town drunk much like Otis is, and Otis shames his brother for what's become of him.
- The Big Bang Theory: Sheldon's older brother George was always considered the family's Black Sheep destined to be a bum. Eventually adult Sheldon is surprised to find out that George was actually the one taking care of the family when Sheldon went to college (after their father's death), and that he has become the successful owner of a tire chain store.
- In Downton Abbey, Edith is considered the plainest, least interesting and least promising of the Crawley sisters. After one suitor gets cold feet at the altar, the next one gets killed in Germany and leaves Edith with an illegitimate daughter, and the third one leaves her after learning of said daughter, her marriage prospects are treated as practically non-existent. Then the third suitor returns, and they happily marry. He is also a fabulously rich Marquess, and Edith ends up outranking her one surviving sister and the entire Crawley clan.
- The Fresh Prince of Bel-Air: Similar to the Married... with Children example below, Hilary is introduced as a spoiled college dropout who is not book smart like her siblings, and her parents are afraid she will never move out of the house or find a job. However from season 2 onwards she finds a lot of jobs and eventually becomes the host of her own talk show, having more overt success than her brother (who is rejected by his dream college) or her sister (whose attempts to become a singer or a model failed).
- Stan Zbornak on The Golden Girls has always been described as a "yutz" by his ex-wife Dorothy's family and even his own mother. The Season 3 episode "Brotherly Love" introduced Stan's younger brother Ted, a successful doctor. The Season 6 episode "If at Last You Do Succeed" has Stan becoming rich after inventing a device to open baked potatoes without burning your fingers, so presumably he has become more successful than Ted.
- On The Last Man on Earth, Tandy was a failure his whole life, while his brother Mike made something of himself and ended up becoming an astronaut. While Tandy was still a screw-up after the virus wipes out most life on the planet, he managed to get a lot of the survivors together, got married, and ended up becoming the de facto leader of the group, while Mike becomes jealous over what Tandy now has, and goes off to find his own place in the new world.
- Married... with Children: Between Bud and Kelly, it was believed that Bud would be the more successful of the two, due to being a lot smarter than Kelly was. However, thanks to Kelly's beauty and sex appeal, she's the one who's had more overt success over the years, having been a model, commercial actress, and television star on numerous occasions.
- Scrubs: J.D.'s brother Dan is a former Big Brother Bully turned Manchild who usually shows up Once a Season to mooch off him. In Season 7, he buckles down, becomes a successful real estate agent, and even tells J.D. to grow up a bit when J.D. becomes jealous at not being the best-off sibling anymore.
- 1 Samuel in The Bible describes how the prophet Samuel came to the home of Jesse to anoint the new king of Israel. Jesse presents his seven sons to Samuel, but leaves out his youngest David. Only when the LORD has rejected the first seven does Jesse mention David. David turns out to be The Chosen One.
- Warhammer Fantasy: Vilitch the Curseling was born a frail cripple to a Norsca tribe's chieftain, and every form of abuse heaped on him (especially by his healthy twin brother Thomin). Where Thomin was an excellent hunter and fighter, Vilitch was eventually apprenticed to the tribe's sorcerer (being good for nothing else) and prayed that he and his brother's positions might be switched around. Tzeentch (god of sorcerers, backstabbers, and mutants) heard his prayers and granted them, fusing Vilitch and Thomin into a single body, Vilitch casting spells and his brain-dead brother's sword skills taking care of any enemy that gets close. During the End Times, the situations switched around again, with Thomin in control of their body and Vilitch now casting spells at his command.
- In Avatar: The Last Airbender, Azula was the celebrated prodigy Fire Nation princess, while her brother Zuko was considered a disgrace and eventually exiled before the start of the series. However, in the final season, Azula's world and mental state started falling apart while Zuko became a better person. In the finale, it culminates in Azula completely losing her mind while Zuko becomes the Fire Lord.
- Theodore Roosevelt was very sickly as a child, while his brother Elliott was healthy, athletic, and outgoing. Yet T.R. ultimately recovered and became an active sportsman, war hero, and eventually President of the United States. Elliott (father of Eleanor Roosevelt) became an alcoholic and died young.
- Richard Carpenter was considered the Favorite and the Star within the Carpenter Family whereas the whole world knows and loves his younger, "less important" sister Karen.
- Mary I and Elizabeth I, daughters of Henry VIII, have gone back and forth as this for much of their lives. After their younger brother Edward VI was born, Elizabeth arguably got the worst of it. She was stripped of her title as princess as Mary was, spent much of her childhood banished to Hatfield, and was later imprisoned in the Tower of London as a young adult. No one expected that Elizabeth would reign as she was farther down the line of succession than her siblings. Elizabeth has since gone down in history as one of the greatest queens England has ever known. Mary, thanks to her ruthless persecution of Protestants during her reign, would be known best as Bloody Mary.